Collapsible folding chair



Feb. 3, 1959 I ARNOLD v 7 2,871,921

COLLAPSIBLE FOLDING CHAIR Filed May 22, 1956 2 Sheet-Sheet 1 FREDRICARNOLD INVENTOR.

BYMMW W.

9 F. ARNOLD COLLAPSIBLE FOLDING CHAIR Filed May 22, 1956 2' Sheets-Sheet2 FIG. 9.

FREDRIC ARNOLD INVENTOR.

United States Patent COLLAPSIBLE FOLDING CHAIR Fredric Arnold, RoslynHeights, N. Y.

Application May 22, 1956, Serial No. 586,612

4 Claims. (Cl. 155-140) This invention relates to collapsible foldingchairs and more particularly to chairs of this type which are formed inlarge degree of lightweight metal tubular elements and which whencollapsed and folded occupy a minimum amount of space.

Lightweight folding chairs formed of tubular metal elements, such asaluminum, are currently being manufactured and marketed. Although suchchairs have many desirable characteristics, considerable difficulty hasbeen encountered in the design and manufacture of chairs of the foldingtype which when erected forms a stable and rigid body support.Furthermore, although the amount of space required in the packaging andshipment of such chairs is considerably reduced by reason of theirfolding characteristics, nevertheless the item still forms a relativelybulky package and occupies considerably more space than is desirable.The bulk presented by the chair even when in folded condition has addedmaterially to the cost of shipment and creates storage problems for thechair when not in use.

It is therefore among the objects of this invention to provide. a chairwhich when erected forms a rigid and stable body support whilemaintaining desirable characteristics of seating comfort for the user.

Another object of this invention is to provide a chair which is capableof being both collapsed and folded so as to occupy a minimum amount ofspace in shipment and storage.

It is also an object of this invention toprovide a chair of thecharacter indicated wherein the repeated collapse and erection of thechair, as Well as the constant folding and unfolding thereof, will notefiect the rigidity and stability of the chair as a body supportingdevice.

Another object of this invention is to provide a chair which is capableof being shipped in collapsed and folded condition and which may bereadily assembled and unfolded without the use of any tools orextraneous fastening elements in a minimum amount of time and with aminimum amount of effort. 7 1

It is also an objectof this invention to provide a chair of thecharacter indicated having flexible seat and back supporting memberswhich are kept in taut and body supporting condition by means providedin the chair structure;

Another object of this invention is to provide a chair of the characterindicated wherein seat and back supporting elements are formed of aflexible material and wherein means are provided for attaching saidflexible material to the chair frame in an efficient and economicalmanner and to achieve an even distribution ofstrain along the attachmentregion.

Other and further objects, benefits and adavntages of this inventionwill become apparent from the description thereof contained in theannexed drawings, specification and claims or will otherwise becomeobvious. It will be understood that the invention herein disclosed maybe employed for other purposes for which the parts, struc-' ture andarrangements are adapted.

2,871,921 Patented Feb. 3, 1959 ice In the accompanying drawings:

Figure 1 is a perspective view of a chair in accordance with the presentinvention;

Figure 2 is a side elevational view of said chair on a. reduced scale;

Figure 3 is a side elevational view of the chair as shown in Figure 2wherein the chair is shown in partly folded condition; a

Figure 4 is a perspective view of said chair on a dilferent scale inpartially collapsed condition;

Figure 5 is a perspective view of said chair in folded condition;

Figure 6 is a cross-section of Figure 5 taken along line 66 thereofshowing the side brace link element arrangement on an enlarged scale;

Figure 7 is a fragmentary cross-section showing the telescopic action ofthe end of a chair leg with respect to a portion of its associatedtransverse brace;

Figures 8 and 9 are fragmentary cross-sections of the seat support barillustrating the manner in which the end edges of the flexible seatmaterial are secured in position; and

Figure 10 is a perspective view of a chair similar to Figure 1 in anexploded form illustrating the relative positions of the chair elementswith respect to the side frames.

In its broad aspect the device comprising the present inventioncontemplates a chair structure wherein a pair of chair side frameassemblies are provided and interconnected by means of flexible seat andback supporting elements or bands. The side frames are arranged so as tobe foldable to occupy aminimum'amount of space. Transverse brace meansare provided for maintaining said side frames in parallel spacedrelationship so that the seat and back bands are stretched therebetweenand retained in taut condition, as for use. Said transverse bracingmeans are additionally disengageably connected with said side frameassemblies to thereby permit them to be detached from the side framesand to be thus collapsed and moved toward each other upon such removalof Said bracing elements to thereby further reduce the amount of spaceoccupied by the chair elements when thus folded and collapsed.

The general construction of a chair in accordance with the instantinvention is illustrated in Figures 1 and 10. As may be seen from saidfigures, the chair comprising 7 the instant invention includes a pair ofside frame assemblies designated generally by the numerals20 and 21which are permanently interconnected by means of a flexible fabric seat22 and a similar fabric back rest 23. The chair structure is completedby a plurality of transverse brace members which maintain the chair inassembled form but are disengageably associated therewith. Thus,

as may be seen from the exploded view of Figure 10, the chair side frameassemblies aremaintain'ed in spaced apart relationship when the chair isassembled for use by means of front and rear transverse brace members 24and 25 respectively which also act as base supports for the chair, atransverse back brace 26 and an intermediate transverse brace 27. Thebracing members 24, 25, 26 and 27 act to maintain the side supportscomprised of the side frame assemblies 20 and 21 in spaced apartrelationship and to thereby stretch the seat and back rest of the chairtherebetween and maintain it in taut condition to form a comfortablerigid and stable body supporting structure, as will more particularly bedescribed hereafter.

As may be seen from Figures 1 and 10, as well as Figures 2 and 3, theside support frame assemblies 20 and 21 are similar for each side of thechair. Said support frames each include a front leg28 and rear leg 29.These legs are advantageously formed of a tubular material, such asaluminum tubing, to provide a structure of adequate rigidity andstrength while maintaining the benefits of a lightweight structure. Eachof the side frame assemblies is additionally provided with an arm rest36 positioned along the upper ends of each set of front and rearlegs.Said arm rest 39 is advantageously formed of a right angled length ofaluminum strip and extends, when the chair is assembled for use,parallel with the floor or ground support. The portion of said arm rest30, which is thus disposed in a horizontal plane, provides a suitablearm rest for the person occupying the chair while the portion of the armrest member disposed in a vertical plane permits the suitable pivotableconnection of the other elements of the side assembly thereto. Each ofthe side frame assemblies is additionally provided with a substantiallyvertically disposed back rest supporting member 31 and a horizontal seatsupporting bar 32. As may be more clearly seen from Figures 2 and 3, theupper extremities of the front and rear legs 28 and 29 are pivotallyconnected to the vertically disposed portion of arm rest 39, as shown at33 and 34. An additional pivotal connection is provided between the rearextremity of the arm rest andthe back supporting member 31 inter mediateits ends as shown at 56. These pivotal connections may be accomplishedby inserting rivets or bolts through registering perforations formedthrough the material of the arm, legs and back support. Each side frameassembly additionally includes a pivotal connection between anintermediate portion of front leg 28 and the horizontal seat supportingbar 32 as shown at 35.

A pivotal connection is provided between the lower extremity of backsupport member 31 and the rear extremity of seat supporting bar 32, asshown at 36 by means of a floating bracing link 37. Said bracing link 37additionally provides a pivot point for rear leg 29 intermediate itsends as shown at 38. As may be more clearly seen from the foregoingfigures and Figure 6, the bracing link 37 comprises a substantiallyL-shaped member formed with arms 41 and 42 respectively. Link 37 may beadvantageously formed of a suitably bent metal rod or wire and isprovided with terminal portions 39 and 40 extending at right angles withrespect to the plane of said L-shaped portion. Terminal portion 39 oflink 37 is passed through registering perforations formed in the lowerextremity of back support member 31 and the rear extremity of seatsupporting bar 32 and constitutes a common pivot pin therefor whileterminal portion 40 of link 37 is passed through perforations formed inthe walls of the tubular member comprising the rear leg 29 as shown at38 and forms a pivot pin therefor. The end of terminal portion 39, whichpasses through the seat supporting bar 32, is provided with a threadedportion and locked in position by means of nut 43. The end of terminalportion 40 is similarly locked in position by means of a locking ring orwasher 44.

It will be apparent from the foregoing that a parallel form of linkageis formed between the arm rest and seat supporting bar paralleltherewith on the one hand and the back support member 31 and the frontleg 28 on the other by reason of this pivotal interconnection. Rear leg29 is pivotally connected at its upper extremity to the arm rest and isprovided with a floating intermediate linkage to the chair back support31 by means of the aforesaid link 37. As a result of this floatinglinkage between the rear leg and the remainder of the chair side supportframe assembly, said side frame may be folded together in the mannerillustrated in Figure 3. Said figure illustrates an intermediate stagein the process of folding the side frame assembly. For the purposes ofclarity of illustration it will be understood however, that the sideframe is capable of being and is actually further folded together to aposition wherein all of the members comprising the side frame aresubstantially parallel and contiguous with each other and occupy aminimum amount of space. Thiscondition is apparent in Figurej wherein anassembled chair is shown in folded condition. The

4 folded condition of each of the side frames would of course be similareven with the transverse braces removed as when the chair is collapsed.

In addition to performing the function of providing a floating linkagebetween the lower and rear extremities of the back support member 31 andseat support bar 32 respectively, the link 37 also performs the functionof acting as a brace for the chair when erected and in use. in thisconnection it should be noted that when the chair is erected for use,the L-shaped portion of the link bears against said leg and urges ittoward the seat brace bar 32. Thus, the longer arm 41 of the side bracerests in parallel contact with a portion of rear leg 29 and serves as abrace therefor to materially reduce or completely prevent lateral swayin the chair when assembled for use. Additionally, the L-shaped portionof the link bearing against the leg body exerts sufiicient friction toact as a lock for the chair to prevent it from being accidentally foldedand further acts as a lock to maintain the chair in folded condition asillustrated in Figure 5 so as to prevent it from being accidentallyopened. The pressure exerted by the link provides a suificientfrictional engagement between the parts to prevent this type ofaccidental movement while at the same time it does not act to increasethe amount of effort required to open or fold the chair to anunreasonable extent.

The chair seat 2 2 and back rest 23 interconnect the side frameassemblies at their respective location. Said seat and back may beformed of any suitable flexible fabric or plastic material, as is wellknown in the art. It is common practice to employ a fabric woven ofsynthetic resin filaments. Heretofore considerable difficulty has beenencountered in mounting such sheets of flexible material securely. Ithas been difiicult to achieve an even distribution of strain along thesecured end edges of the fabric and as a result of this the fabric hasoften become torn or otherwise disengaged from its point of securement.In order to obviate this difficulty the instant chair employs a clampingbar arrangement for securing the end edges of the seat and back fabricor material to the seat supporting bar and back support respectively.Thus, as may be seen more particularly from Figures 8 and 9, theinstantinvention employs a clamping bar 45 which is coextensive with the widthof the fabric to be attached to the seat supporting bar. Clamping bar 45is formed of a thin strip of metal from the body of which tongues 46have been struck as by stamping. The seat supporting bar is providedwith perforations therethrough at points in registration with thetongues 45 extending from said clamping bar 45. In order to secure theend edge of the fabric to the seat supporting bar, the end portionthereof is folded upon itself and around clamping bar 45 and the tongues46 are forced through the material. The clamping bar is then broughtinto position against the seat supporting bar 32 and tongues 46 arepassed through the perforations 47 formed in said seat supporting barand the ends of said tongues are bent over to firmly secure saidclamping bar to the seat supporting bar. By means of this arrangementthe end edge of the fabric comprising the seat is anchored along itsentire width and the stress to which the seat is subjected when in useis evenly distributed along the entire length of the seat supportingbar. In the same manner a clamping bar is employed in connection witheach back support to firmly secure the flexible chair back material tosaid back supports 31. In this. case however, perforations are providedin the body of the wall of the tube in registration with the projectingtongues of the clamping bar and the backing material is again foldedupon itself and around the clamping bar. The tongues of the clamping barare then passed through the perforations in the tube wall. In order tobend the tongue ends over against the interior of the tube wall, it ismerely necessary to force a cylindrical mandrel into the interior of thetube thereby automatically bending over the tongue ends against theinterior wall of the tubing forming the back supports for the chair. Ineach case the clamping bar serves to anchor the end edge of the backrest material along the entire width thereof and serves to achieve aneven distribution of stress therealong.

From the foregoing description it will be apparent that a structure isachieved at this point wherein two foldable side frame assemblies areinterconnected by means of sheets of flexible fabric which comprise theseat and back rest for the chair respectively. Since there are notransverse rigid members interconnecting the side frames at this point,said side frames may be brought into close proximity as is illustratedin Figure 4. In fact they may be brought into actual contact with oneanother. It will be further apparent that when so brought into contactand folded as indicated in Figure 3, the side frames and seat occupy avery small volume of space.

The chair structure is completed by means of transverse front and rearbase brace members 24 and 25. These base brace members are formed oftubing similar to that from which the chair legs are formed but are of asmaller diameter. Front and rear base brace members 24 and 25respectively are of substantially U-shape and comprise horizontal baseportions 49 from which there extend the vertically disposed arms 50. Asheretofore indicated the base members 24 and 25 are formed of tubingwhich is of smaller diameter than the diameter of the tubing whichcomprises legs 28 and 29 of the chair so that the arms 50 are adapted tobe telescopically received within the ends of said legs as may be seenmore clearly in Figure 7. The tubing forming the legs and base membersis so dimensioned as to permit the snug fit between these parts butnevertheless to permit the insertion and removal of the base membersfrom the chair legs. In a similar manner a substantially U-shapedtransverse back brace member 26 is provided for the back of the chairand is similarly U-shaped having a horizontal transverse portion 52 fromwhich arms 53 depend. Said arms are adapted to be similarlytelescopically received within the open ends of the tubular memberscomprising the back supports 31 for the chair. An intermediatetransverse brace 27 is provided and comprises a tubular member havingflattened ends 48 formed with substantially right angled bends which areadapted to be received in slots 51 formed in the wall of the tubingcomprising the front legs 28.

The manner of assembling the chair may be more clearly seen in Figures 4and 10. As may be seen from said figures, in the first step ofassembling or erecting the chair the side frame assemblies are unfoldedto assume the position indicated in Figure 4. The side frames are thenmoved to the spaced apart parallel relationship indicated in Figure 10,in which position the transverse back a brace member 26 isplaced intoposition by inserting the dependent arms 43 thereof into the upperextremities of the back rest supporting members 31. The flattened andbent ends 48 of intermediate transverse brace 27 are then inserted intoslots 51 formed in the wall of the tubing comprising the front legs 28.Thereupon the upwardly extending arms 50 of the transverse base bracemembers 24 and 25 are telescopically inserted into the lower extremitiesof the front and rear legs 28 and 29 respectively. in this connection itshould be noted that the fabric forming the seat and back rest isadvantageously somewhat shorter than the distance between the arms ofthe brace members so that in inserting the brace members into positionthe fabric of the seat and back rest is made taut and is slightlystretched so that the tension of the seat and back rest'fabric serves toincrease the friction between the ends of the brace members and thewalls of the leg and back rest supporting members thereby assuring thatthese members will be maintained firmly in relative position and thatthe entire chair structure is rigid. In this connection it should alsobe noted that when a person is seated in a chair the additional tensionapplied to the seat and back rest is communicated to the legs and vfabric parallel with the warp threads.

back rest supporting members so that additional pressure is appliedagainst the ends of the various transverse braces, thus additionallyassuring rigidity for the chair structure. The dis-assembly of the chairis readily ac complished by reversing the process and withdrawing theends of the brace members from their position in the leg and back restsupporting members. The side supporting frames may then be readilyfolded and brought into contact with each other in order to completelycollapse the chair. A convenient form of accomplishing this is to windthe fabric of the seat and back rest around one of the folded sideframes thereby forminga neat and compact bundle which occupies a minimumamount of space since the legs, back rest supports, the arm rests andthe seat supporting bars are in substantial parallelism and contact witheach other. The tranverse braces may then be positioned so that theirbase portions are parallel with the members of the folded side frames,as is the horizontal transverse portion of the transverse back brace.The intermediate brace is, of course, similarly positioned. The entirebundle thus comprises a group of longitudinally extending elements inclose proximity with each other and occupies a volume determined largelyby the combined area of their cross-sections and length. Thus, a chairof this type and of a size adapted to be occupied by an average adultperson may be conveniently packed into a rectangular container 5 /2 x 5/2 X 28". The compact manner in which the instant chair may be foldedand collapsed to occupy a small volume of space, as indicated, resultsin a very substantial savings in storage space and shipping cost.

.The chair structure itself is. considerably improved by the employmentof the brace arrangement hereto:

fore disclosed. The intermediate brace 27 contributes appreciably to therigidity of the chair structure and resists twisting forces to. whichthe interconnected side frames are subjected during use. In thisconnection it should be noted that the ends of said braces are flattenedso as to provide a considerable transverse bearing surface formed by theparallel walls of the flat tube ends. The flat ends 48 fit snugly intothe elongated slots .51 which have complementary parallel disposedspaced side walls thereby causing said ends to bear against the walls ofthe slot and to resist the torque or twisting action to which theinterconnected side frames are subjected.

The method of connecting the fabric seat 22 and the back rest 23 isadditionally significant in that the need for sewing along the marginaledges of these elements is entirely eliminated. In this connection itshould be noted that where, as heretofore, sewing has been employed tosecure the end edges of the fabric, the sewing thread forms one of theweakest links in the connection.

This results from the fact that the entire seat or back rest assembly isheld 'by the sewing thread. There are limitations in the employment ofheavy gauge threads and even these have not proven to be satisfactorysince they tend to break under the constant abrasive action against thethreads of the fabric to which they are subjected in use, particularlyas the weight of the user is shifted. The sewing threads thereforeconstitute one of the first points at which the fabric breaks loose. Theinstant construction permits the entire elimination of this weak pointof connection and additionally results in substantial economies inmanufacture. It should additionally be noted that the tongues 46 of theclamping bars 45 are disposed so that their faces extend trans verselyacross the clamping bar and they thus enter the These are the threadswhich extend between and interconnect the side frames, extendingtransversely across the chair. By disposing the tongues parallel withthese warp threads, they are not injured or broken as the tonguespenetrate the fabric since the tongues pass therebetween. Although someof the woof threads extending parallel with the clamping bar and fabricsupporting elements may be im 7 jured, this does not materially reducethe strength of the fabric. It is the warp threads which are subjectedto the considerable tension and abrasion in use and consequently thebreakage of even one or a small number of these threads would form aninitial point of weakness at which a tear could begin. By disposing thetongues in the manner indicated, these threads are in no-wise injuredduring the attachment process or by the attachment means.

I have here shown and described a preferred embodiment of my invention.It will be apparent, however, that this invention is not limited to thisembodiment and that many changes, additions and modifications can bemade in connection therewith without departing from the spirit and scopeof the invention as herein disclosed and hereinafter claimed.

I claim:

1. A chair comprising a pair of side frames, each of said side framesincluding a front and rear leg member, arm rest and back support membersand a seat supporting bar, said members and bar comprising each framebeing pivotally interconnected for folding movement, a detachabletransverse brace member interconnecting the front leg members of saidframes and a detachable transverse brace member interconnecting the rearlegs of said frames, said brace members each including a horizontalportion and being detachably interconnected with the terminal portionsof said leg members, a transverse back brace provided with a horizontaltransverse portion detachably interconnected with said back support, atransverse brace interconnecting the intermediate portions of said frontlegs, a flexible seat and a flexible back rest secured to said seatsupporting bars and extending between said seat supporting members andsaid back supports.

2. A chair comprising a pair of side frames, each of said side framesincluding a front and rear leg member, arm rest and back support membersand a seat supporting bar, said members and bar of each frame beingpivotally interconnected for folding movement, a pair of U-shapedtransverse base brace members interconnecting the front and rear legs ofsaid frames respectively, said base members including horizontal groundengaging portions and being provided with arms extending therefromdetachably interconnected with the terminal portions of said legmembers, a transverse U-shaped back brace provided with a horizontaltransverse portion and arms depending therefrom detachablyinterconnected with the back supports of said frames, a transverse braceinterconnecting the intermediate portions of said front legs, a flexibleseat and a flexible back rest secured to the seat supporting members andsaid back supporting members of said frames respectively and extendingtherebetween.

3. A chair comprising a pair of side frames, each of said side framesincluding a front and rear leg member, an arm rest and a seat supportingbar and a back support member, said arm rest and back support beingdisposed in horizontal spaced apart relationship when said chair iserected for use, said front and rear leg members and said back supportbeing substantially vertically disposed, a pivotal connection betweenthe upper extremity of said front leg member and the forward end of saidarm rest and a pivotal connection between the forward extremity of saidseat supporting bar and at an intermediate portion of said front leg, apivotal connection between the upper extremity of said rear leg and saidarm rest at an intermediate portion of said arm rest, an additionalpivotal connection between said back rest supporting member at anintermediate portion thereof with the rearward extremity of said armrest and a common pivotal connection between the lower extremity of saidback rest supporting member, the rearward extremity of said seatsupporting bar and an intermediate portion of said rear leg member, saidcommon pivotal connection being comprised of a substantially L-shapedlink, said link being provided with terminal portions at the extremitiesthereof extending normally with respect to the plane thereof, one ofsaid terminal portions forming a pivot pin for the lower extremity ofsaid back rest support and said seat supporting bar, the other of saidterminal portions comprising a pivot pin for the intermediate portion ofsaid rear leg member.

4. The device according to claim 3 wherein one of the arms of saidL-shaped linking member is disposed parallel with and bears against theintermediate portion of said rear leg to form a brace therefor.

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